NATO defense ministers say the alliance is beginning to plan for a withdrawal of all NATO-led forces from Afghanistan by the end of the year.
Meeting in Brussels on February 27, NATO defense chiefs said President Hamid Karzai's refusal so far to sign an already drafted agreement with the United States on the status of troops in the country after 2014 is reducing the chances that such an agreement will be signed.
NATO Secretary-General Anders Fogh Rasmussen said that without the "necessary" legal framework, NATO troops cannot remain in Afghanistan.
"But we need to be very clear: finalizing the planing for our new mission depends on completing the NATO Status of Forces Agreement. As we have said from the start, the NATO Status of Forces Agreement cannot be concluded until the Bilateral Security Agreement between Afghanistan and the Untied States is signed," Rasmussen said.
"The delays in signing this agreement have made our task more difficult and there is a strong need to consider the impact on our planning."
NATO has been planning to keep some troops in Afghanistan after 2014 to train and assist Afghan forces, but now will begin planning for the so-called "zero option" -- a complete withdrawal.
Karzai, who is due to leave office after Afghanistan’s April elections, has sought several concessions from Washington in connection with the Bilateral Security Agreement.
U.S. Defense Secretary Chuck Hagel said time for reaching an agreement with Kabul is growing short.
"The longer we go without a Bilateral Security Agreement and a NATO Status Of Forces Agreement, the more challenging it will be for United States and other ISAF nations to support, plan, and execute this post-2014 mission. That is why earlier this week, [U.S.] President [Barack] Obama directed the U.S. military to begin additional contingency planning," Hagel said.
"We will ensure that adequate plans are in place to accomplish an orderly withdrawal by the end of the year, should the United States not keep any troops in Afghanistan after 2014."
Hagel said he's concerned that a complete international withdrawal from Afghanistan could lead to an "erosion of confidence" in Afghan soldiers and police.
Based on reporting by Reuters, AFP and AP